Mateo,
The boom rotates to windward, the sail goes to leeward. Hopefully i will have it working, or not, before you need to decide. Note that i am not yet sufficiently confident in the idea to throw away the wishbone!
Adrian,
The Elementarry would look like a small Bucket List, with a windward hull of whatever size you required. The pop up cabin would remain, but would be influenced by the work we are currently doing on the Exhilarator 40.
The investment in infusion is quite low. A pump from Ebay for $150 (or make your own from a fridge compressor or a milking pump), a few dollars worth of hardware plumbing (spiral wrap, stiff hose, cheap 3 strand string, couple of door stops, sheet of plastic), all of which are reusable.
The vac bag is cheaper by the roll, but to get started, a few metres/yards from your resin supplier will suffice. The tacky tape to seal the bag can be replaced by brown packaging tape, but best to get a roll of the tacky tape and start with that to eliminate possible problems. It is easier to stop leaks with tacky tape as it usually only needs downwards pressure. Packing tape needs more attention to seal leaks.
The resin will be ~10% more expensive than hand laid resin. The mould and/or table are sheets of mdf or similar, so cheap. For your first test, a sheet of glass is a good option as it allows you to watch the flow from both sides, but this is not essential. Peel ply can be sourced by the roll from a dress maker supplier, but to start with, get a few metres from the resin supplier.
The learning curve is steep, but much less so than that required to cut and set up a set of frames, or to fit a bulkhead in a 4 sided space. And it is low stress. You have as long as you like to set it up (feel free to send me photos or questions if you want your set up checked. Or give me some warning and Skype me and we can discuss it) before the bag goes on. And take as long as you like to find and seal the vacuum leaks and get the bag settled. With a small first job, this will not take long. Then mix the resin, drop the inlet tube in it, release the clamp (needle nose vice grips, g clamp on 2 bits of scrap wood, kite surfer rib closures, etc) on the tube and watch it happen. If you did not mix enough resin (I rarely do, hate wasting the stuff), close the clamp, mix more resin and repeat.
On big jobs it is possible to run the feed across the job so that it is wet out one area at a time. This is even less stressful.
If the wet out leaves dry areas (due to a poor layout), either poke a syringe of resin into the area and let the vacuum suck it out, or use a football pump needle valve attached to your vac line (via a V or T connector) to suck surrounding resin into the dry area. When it is done, pull out the syringe/needle valve and apply a piece of packing tape to seal the hole. This is highly unlikely with the simple infusions required for Intelligent Infusion and even less likely on a sample. It would probably require special preparation to achieve it.
Drop me a line, or ask questions on here if you want to have a go.
The lower the temperature, the thicker the resin, the slower it flows. See the resin makers instructions for what is too low. Heating small samples is very easy (light bulbs, blower heaters, electric blankets etc). Bigger jobs not so easy, but mdf is a pretty good insulator and both the mould and the table are easy to cover so heating is less of a problem than for say an upturned hull.
Emergency stopping. Mike says it better than I can. The ability to stop very quickly by releasing the sheet and pulling on the new one is handy. As is being able to sail backwards out of sticky situations. Or to pick up a hat or crew lost overboard.
Rob,
No gooseneck as such. The boom is bonded to a saddle which sits against the mast. There is a lip on the mast to stop it slipping down and shock cord around the saddle above the boom to keep it against the mast. The sheet and outhaul/vang are both pushing the boom against the mast so the elastic is only needed when hoisting/lowering the sail. The boom must be able to rotate 360 degrees or the gooseneck gets ripped off if/when you are caught aback. The lazy sheet runs through the end of the boom, then to the sail.
The hoops work if the mast is not tapered. For a tapered mast, the straps need to be adjustable, which also makes them easier to raise/lower. Hopefully a single line will tighten them all at once. Otherwise, it gets more complex, but still worth doing, I think. Initially the straps will be narrow seat belt material. If this is too much friction there are a variety of ideas to reduce it.
The sail sits to leeward of the mast. Makes the high pressure separation bubble smaller, the low pressure (windward side) bubble bigger. In theory, this is more efficient (see cross sections of leading edge inflatable kites). We will see, but I would accept equally efficient as the weight, complexity and cost savings vs track and cars is large. And it would be a big boost for unstayed masts in general.
Whether this and the other savings are worth transferring to the other harrys we will know when BL sails. Although i am wishing I had not chopped up Elementarrys mast as it would be nice to try them on a 7m mast rather than a 17.
I think BD has a carbon track. Rare Bird does and Rudolph made a sample and tested it to destruction with very impressive results. Both have plastic cars. The hoops were on the boat in Luc's photo.
Mike, Luc
Ta.
On Sat, Apr 9, 2016 at 11:45 PM, Mateo mateo002@yahoo.ca [harryproa] <harryproa@yahoogroups.com.au> wrote:
Does the boom rotate to enable shunting?
On Apr 9, 2016, at 5:17 AM, "Rob Denney harryproa@gmail.com [harryproa]" <harryproa@yahoogroups.com.au> wrote:Ta. Me too.Just added a new picture to the Bucket List page. A cockpit, no less! http://harryproa.com/?page_id=1173In other Bucket List news there is now someone working on it part time. The lee hull is almost ready for closing up. The hull halves were not built using as much Intelligent Infusion as they would be now, so we had to add the bulkheads, ring frames and mast step, shape the foam bows and do some work on the joining flanges. This was after the poor builder had to grind out the plumbing which I had put in without plastic under it in the rush to get it sealed up before I left. Pictures so far are pretty ordinary, will post some decent ones when I have them.The rig has undergone some simplification.A single boom instead of a wishbone. This decision was made a couple of days after i finished building the wishbone, which weighs 15 kgs. The single boom will be less than 5.The mast no longer rotates. This saves the cost of the bearings (couple of hundred bucks each) and more importantly the work getting the mast round and the bearings accurately aligned. This is much easier when you have the filament winding machine to use as a lathe, but is still work which has to be done.There is no sail track or sail slides. This is another signficant weight and cost saving as well as a few more things that cannot go wrong as they are not there. The sail is attached to the mast using straps, an idea which started when I was on Blind Date moored alongside a Dutch barge with it's mast hoops.A single line, no moving parts, light weight, fail safe halyard lock which works at each reefing point. This solves the problem of the luff loosening as the mast bends and allows a much thinner halyard.The rudders are shafted rather than in cassettes. They can still be lifted for balance and shallow water, but only 600mms/24", leaving 400mm/16" in the water. It may end up being less as the rudder depth looks right, but are deeper than science suggests. They can be tilted to get them clear of the water. This is simpler and more robust than the cassettes.On Sat, Apr 9, 2016 at 7:39 PM, robriley@rocketmail.com [harryproa] <harryproa@yahoogroups.com.au> wrote:yes the site looks great Rob
like that Scandinavian feel to the design
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Posted by: Rob Denney <harryproa@gmail.com>
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